Process for manufacturing upholstering material



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United States Patent O PROCESS FOR MANUFACTURING UPHOLSTERING MATERIAL Joseph Wollseifen, Wuppertal-Elberfeld, and Karl Schieclr, Kurt-Jrgen Schulze, and Fritz Roggenbau, Oberbruch, Germany, assignors, by mesne assignments, to American Enka Corporation, Enka, N. C., a corporation of Delaware Application March 22, 1951, Serial No. 217,048 In Germany July 29, 1949 Public Law 619, August 23, 1954 Patent expires July 29, 1969 8 Claims. (Cl. 154-90) This invention relates to a process for the manufacture of material for use in upholstering from artificial threads by a continuous operation.

In the past for a very long time upholstering material has been made by crimping long staple natural liber material by overtwisting into cable form, releasing the twist, teasing out and using the loosened liber for stufng upholstery. Upholstery was later made by building in steel springs so that hair upholstering material served only as an overlay in superimposed fashion on a system of steel springs. Recently, loose natural or artificial fiber material has been arranged in layers and maintained in a loose condition by the application of rubber latex and subsequent vulcanization which maintains the upholstering material more elastic.

The present invention provides a process for the manufacture of upholstering material from artificial threads such as synthetic resins and artificially spun cellulose and cellulose derivative laments by a continuous operation, wherein freshly spun artificial monolar threads (articial horsehair) are gathered into a cable, the latter after pre-drying is overtwisted and stretched, the crimping thus produced is xed by a further drying step, the cable is loosed to form a crimped band of parallel crimped threads, the crimped band is sprayed with a binder which remains elastic after drying and/ or vulcanization, for example an emulsion of rubber latex, and a number of such bands are superposed layerwise, pressed and vulcanized in a manner, known per se, to produce a band of upholstering material which can be cut into desired sizes.

According to a modification of the process, instead of uniting several crimped bands to form a band of upholstering material, a crimped band is displaced into loop form with the loops partially superposed.

Figures l, 2 and 3 show diagrammatically one form of apparatus for performing the invention.

Referring to Figures 1, 2 and 3 the invention is practiced as follows: The threads coming from the spinning points 1 to 6 are gathered and led in the form of a cable through the after-treating baths 7. Then they pass through the pre-drier 8 in a raising and descending path, are collected on large bobbins 9 and from there are led through the twisting devices 10 and 11. At the end of a drying pipe 12 in which the twist is xed, there are twisting devices 13, 14 which maintain the twist in the cable. After leaving the devices 13, 14 the cable untwists itself. By means of the spreading device 15 the cable is spread to a crimped band which is received by rollers. From several of such rollers 16 the crimped bands fall vertically towards the bottom onto an endless conveyor 17 which leads the crimped fleece consisting of several layers to the spraying device 18. Here the binding agent is supplied. From nozzles 19 hot air ows out whereby a portion of the water content of the binding-agent-emulsion is evaporated. Rollers 20 now press ice the crimped fleece onto the endless conveyor 21 thereby producing the necessary elasticity and the combination of the individual crimped threads with the binding agent. In oven 22 the vulcanizing of the binding agent is carried out.

The process of the invention affords a fundamentally different method of manufacturing upholstering material from artificial monolar threads, so called artificial horsehair. The process involves a simplified sequence of operations and produces upholstering material of irnproved properties. Use :can be made of devices which are becoming more and more used in the artificial thread industry, by means of which freshly spun threads are brought directly into a suitable condition for further treatment. By means of the process of the present invention the crimped bands produced directly from the freshly spun thread cables can be formed in a continuous operation into upholstering material which thereafter need only be cut into the desired sizes and they are then ready to be used by upholsterers.

In a preferred embodiment of the process monofilar threads are gathered into cables and the latter, after washing, are passed into a drying apparatus where they are pre-dried. The cable is then twisted by means of a twisting device. The twist is increased until the yarn is overtwisted, the curvature of the crimp thus produced by the twisting device being dependent upon the thickness of the cable. A second twisting device ensures that the twist is maintained. Between these two twisting devices a drying zone serves to x the overtwist. After leaving the second twisting device the cable untwists itself in the opposite direction. The cable is now loosened up in such a way as to form a crimped band consisting of endless threads lying parallel to one another. ln order to produce the upholstering material, either a number of crimped bands from the take-off rolls are superposed on a conveyor belt so as to produce a band of upholstering material of the desired weight per square metre, or else a crimped band is fed directly to the conveyor belt and is shaped into loop form of suitable loop displacement and pitch with appropriate increase in height to form the band of upholstering material. The layer of threads lying on the conveyor belt at any given time is sprayed with an elastic binder, for example rubber latex, containing the necessary vulcanizing additions, before the next crimped band is superposed layerwise upon it. The structure so formed passes at the end of the conveyor belt into a pressure .device where it is compressed to the desired thickness and is then stabilized by vulcanization of the rubber latex mixture. The bands of upholstering material so produced can now be cut up into pices of desired sizes or can be rolled up and shipped to the upholsterer in this form.

By means of the process of the invention it is possible to produce upholstering material which only needs to be cut up into the shape desired by the upholsterer. Because of the crimping effect which is carefully produced and preserved during the process of manufacture, an upholstering material is produced which is distinguished from previously known upholstering material not only by its economy in production, but also by its improved properties as upholstering material. A method of testing has been devised for the upholstering material which consists in periodically loading the material to be tested and then removing the load after a definite period. Such tests have shown that the upholstering material produced from this endless fiber material has better elastic properties than upholstering material produced from staple material arranged at random. In

the tests, loads of approximately 300 grams per squarev centimeter were applied for a period of approximatelyl minute. After testing for 5-10 honra-depending upon the weight per square metre of the upholstering material, the heights in the loaded and unloaded condition still varied an immaterial amount. Tests on a medium 'weight upholstering material with a weight per square meter of 2000 grams and a height of 50 mm. showed that a test piece consisting of endless parallel threads had a higher elasticity than a test piece produced from the same material which had however been cut into staples and the latter arranged at random. The upholstering material composed of material arranged at random was compressed in the middle at the end of a test period of 7 hours (7 60=420 loadings and unloadings) to a thickness of 7.4 mm. and on unloading was restored to a thickness of 19.0 mm., While upholstering material produced by the process .of the present invention was compressed in the middle to 7.2 mm. and on unloading was restored to ya thickness of 20.8 mm. The elasticity, which is expressed as the difference in height in the loaded and unloaded condition, is therefore approximately 10% better for upholstering material produced by the process of the present invention. The upholstering material produced by the process of this invention also has the advantage as compared to stuthng produced from staple material that it has practically no thread or fiber ends, so that the latter do not project through the material when the upholstery is used for chairs or the like and the usual overlays of webbing and protective material can be omitted. The process may be so arranged that the uppermost layer during the building up of the bands of upholstering material consists of a fiber material of finer titer which gives the upholstering material a smoother surface. It has also been found that the elasticity of the upholstering material can be varied by superposing layerwise crimped bands of a different titer. For example the uppermost and lowermost layers may consist of artificial threads of a titer of 400 deniers and the intermediate layers may consist of artificial threads of a titer of 2000 deniers. A very large number of combinations may be built up in this way and must be adapted in each case to the intended use. It is preferable to use a titer of less than 500 deniers for the outer layers.

As the binder for the fixing of the crimped bands or of the loops a material is employed which will remain elastic after drying or Vulcanizing, i. e. does not render the fibers brittle or fragile. Excellent results have been attained with a natural rubber latex which in Wellknown fashion contains vulcanization additions. Favorable results were also obtained with prevulcanized latex concentrates, such as are on the market, for example, under the designation Revultex, or with emulsions of artificial rubberlike materials, for example of mixed polymerizates of butadiene-styrene (Bunalatex) or of chlorobutadiene polymerizates (neoprene latex).

For many purposes artificial resins are also suitable as binders, although the above-mentioned rubberlike sub-v stances are preferred. For example, the emulsions obtainable on the market under the designations Movilith, Acronex, or Luthophan and similar emulsions can be employed, which contain as basic substances polymerization products of vinyl acetate, vinyl chloride, and other polymerizable unsaturated compounds.

The following example discloses how the process of the invention may be carried into effect.

400 freshly spun monolilar threads having an individual titer of 1000 deniers coming from one or more spinning machines were washed in the form of a cable and predried to a Water content of approximately 50%. The cable was fed to a twisting device, 'known per se, which produces an overtwist. The overtwist of the cable was maintained by a subsequent twisting device and the cable between the two twisting devices 'passed through a drying tube where it was dried to a water content of 12% so as to stabilize the crimping. The cable leaving the second twisting device untwisted itself automatically and was spread out into a crimped band of 60 cm. width and wound up on rolls in this Width. Seven such rolls were sprayed in the above described manner with a 60% rubber latex mixture containing the necessary vulcanizing additions. The multi-layered endless structure produced in this way having a Width of 60 cms. and a height of approximately 10 cms. was continuously compressed by means of a pressing device to a height of 5 cms. The band of upholstering material thus produced was pre-dried at 75 C. to evaporate the water introduced with the rubber latex and was then vulcanized at C. in a heating zone. On leaving the heating zone the band of upholstering material was dusted with talcum and made up in a form ready for sale.

What we claim is:

l. A process for the manufacture of upholstering material from continuously produced artificial thread comprising assembling .freshly spun artificial threads into a cable, pre-drying said cable, then twisting said pre-dried cable, then further drying `said twisted cable, then loosening said cable to form a crimped band of parallel crimped threads, then spraying said crimped band with an elastic binder and then vulcanizing said band to produce la band of upholstering material.

2. A process for the manufacture of upholstering material from artificial threads by a continuous operation, comprising gathering freshly spun artificial monoiilar threads spun alongside one Vanother into a cable, pre-drying said cable, overtwisting said pre-dried cable, xing by a further drying step said twisted cable, loosening said cable to form a .crimped band of parallel crimped threads, spraying said crimped band with an elastic binder, superposing a number of such bands layerwise and then pressing and vulcanizing said bands to produce a band of upholstering material which can be cut into desired sizes with said binder retaining elasticity in the finished form.

3. A process for the manufacture of upholstering material from continuously produced artificial thread comprising assembling freshly spun artificial threads into a cable, pre-drying said cable, then twisting said pre-dried cable, then further drying said twisted cable, then loosening said cable to form a crimped band of parallel crimped threads, then spraying said crimped band with an elastic binder :and then setting saidY elastic binder to produce a band of upholstering material.

. 4. A process for theV manufacture of upholstering material from continuously produced artificial thread comprising assembling freshly spun artificial threads into a cable, pre-drying said cable, then twisting said pre-.dried cable, then further drying said twisted cable, then loosening said cable to form a crimped band of parallel crimped threads, then Ispraying said crimped band with an elastic binder, then superposing a plurality of said bands and then pressing and vulcanizing said bands to produce a band .of upholstering material. 1

5. A process as lset forth in claim l wherein said binder comprises #an emulsion of rubber latex.' v

6. A process as .setforth in claim 1 wherein said band of upholstering material comprises monofilar threads.

7` A process as set forth in claim 5 wherein monolar threads of a titer of less than 500 deniers are used as the uppermost crimped band in the production of upholstering material.

8. A process for the manufacture of upholstering material from continuously produced artificial thread `comprising assembling eshly spun artificial threads into a cable, pre-drying said cable, then twisting said pre-dried cable, then further drying said twisted cable, then loosening said cable to form 'a crimped band of parallel crimped threads, then superposing a plurality of said bands with the bands ydisplaced into a loop form with the loops partially superposed. then spraying said crimped band with an elastic binder and then setting said binder to produce upholstering material.

(References on foiiowing page) References Cited in the 111e of this patent UNITED STATES PATENTS Davison May 14, 1935 Hurst et al. Sept. 22, 1936 5 Metcalf et a1. July 20, 1937 Knowland et al. Ian. 3, 1939 Seigle etal Mar. 7, 1939 Redman June 24, 1941 Caldwell Sept. S, 1942 10 Taylor Apr. 30, 1946 6 Alderfer Dec. 2, 1947 Jahant May 4, 1948 Heberlein et 'al Mar. 8, 1949 Bloch Apr. 5, 1949 Browne et al. July 19, 1949 Caspe Mar. 21, 1950 Modigliani Mar. 27, 1951 Billion Aug. 14, 1951 Browne Oct. 16, 1951 Modigliani Nov. 6, 1951 

3. A PROCESS FOR THE MANUFACTURE OF UPHOLSTERING MATERIAL FROM CONTINUOUSLY PRODUCED ARTIFICIAL THREAD INTO A PRISING ASSEMBLING FRESH SPUN ARTIFICIAL THREADS INTO A CABLE, PRE-DRYING SIAD CABLE, THEN TWISTING SAID PRE-DRIED CABLE, THEN FURTHER DRYING SAID TWISTED CABLE, THEN LOOSENING SAID CABLE TO FORM A CRIMPED BAND OF PARALLEL CRIMPED THREADS, THEN SPRAYING SAID CRIMPED BAND WITH AN ELASTIC BINDER AND THEN SETTING SAID ELASTIC BINDER TO PRODUCE A BAND OF UPHOLSTERING MATERIAL. 